C $Header: /home/ubuntu/mnt/e9_copy/MITgcm_contrib/ocean_inversion_project/code/ptracers_init.F,v 1.2 2003/09/23 04:34:23 dimitri Exp $
C $Name:  $

#include "PTRACERS_OPTIONS.h"

CBOP
C !ROUTINE: PTRACERS_INIT

C !INTERFACE: ==========================================================
      SUBROUTINE PTRACERS_INIT( myThid )

C !DESCRIPTION:
C     Initialize PTRACERS data structures
C     This file is customized to compute CO2 perturbations from
C     30 ocean regions for Gruber's ocean inversion project.

C !USES: ===============================================================
      IMPLICIT NONE
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "GRID.h"
#include "PTRACERS.h"


C !INPUT PARAMETERS: ===================================================
C  myThid               :: thread number
      INTEGER myThid

C !OUTPUT PARAMETERS: ==================================================
C  none

#ifdef ALLOW_PTRACERS

C !LOCAL VARIABLES: ====================================================
C  i,j,k,bi,bj,iTracer  :: loop indices
      INTEGER i,j,k,bi,bj,iTracer,iMonth
      CHARACTER*(10) suff
      _RL SumPtracer
CEOP
        
C Loop over tracers
      DO iTracer = 1, PTRACERS_num

C Loop over tiles
       DO bj = myByLo(myThid), myByHi(myThid)
        DO bi = myBxLo(myThid), myBxHi(myThid)

C Initialize arrays in common blocks :
         DO k=1,Nr
          DO j=1-Oly,sNy+OLy
           DO i=1-Olx,sNx+Olx
            pTracer(i,j,k,bi,bj,iTracer) = 0. _d 0
            gPtr(i,j,k,bi,bj,iTracer)    = 0. _d 0
            gPtrNM1(i,j,k,bi,bj,iTracer) = 0. _d 0
           ENDDO
          ENDDO
         ENDDO

C end bi,bj loops
        ENDDO
       ENDDO

C end of Tracer loop
      ENDDO

C Read from a pickup file if nIter0 is not zero
      IF (nIter0.NE.0) THEN
C--     Suffix for pickup files
       IF (pickupSuff.EQ.' ') THEN
         WRITE(suff,'(I10.10)') nIter0
       ELSE
         WRITE(suff,'(A10)') pickupSuff
       ENDIF
       CALL PTRACERS_READ_CHECKPOINT( nIter0,myThid )
      ENDIF

C     Initialize pTracerMasks
      CALL PTRACERS_READ_MASK ( mythid )

C     Initialize pTracerTakahashi
      CALL PTRACERS_READ_Takahashi ( mythid )

C     Normalize pTracerTakahashi so that 1e18 mol/yr is released
C     from each model region defined in pTracerMasks.
C     It is assumed that each year is 365.25 days (31557600 s)
C     long and that each month is 2629800 s.

      DO iTracer = 1, PTRACERS_num
       SumPtracer = 0.
       DO bj = myByLo(myThid), myByHi(myThid)
        DO bi = myBxLo(myThid), myBxHi(myThid)
         DO j=1,sNy
          DO i=1,sNx
           DO iMonth=1,12
            SumPtracer = SumPtracer + 2629800. * rA(I,J,bi,bj) *
     &             pTracerMasks    (I,J,iTracer,bi,bj) *
     &             pTracerTakahashi(I,J,iMonth ,bi,bj)
           ENDDO
          ENDDO
         ENDDO
        ENDDO
       ENDDO
       _GLOBAL_SUM_R8( SumPtracer, myThid )
       DO bj = myByLo(myThid), myByHi(myThid)
        DO bi = myBxLo(myThid), myBxHi(myThid)
         DO j=1,sNy
          DO i=1,sNx
           DO iMonth=1,12
            IF ( pTracerMasks(I,J,iTracer,bi,bj) .eq. 1. )
     &             pTracerTakahashi(I,J,iMonth ,bi,bj) = 1.e18 *
     &             pTracerTakahashi(I,J,iMonth ,bi,bj) / SumPtracer
           ENDDO
          ENDDO
         ENDDO
        ENDDO
       ENDDO
      ENDDO

#endif /* ALLOW_PTRACERS */

      RETURN
      END